We find that the fluid produced by the well (oil or water) do not flow to the surface alone; therefore, there are several types of extraction or artificial lift including Electric Submersible Pumps (ESP), Progressive Cavity Pumps (PCP), which requires electrical heaters in the bottom of the well—in case of heavy oil (API low viscosity)—to lighten oil and pump it easily. As these systems are electrical, they need to be plugged to sources of electricity in the surface of the well using electric cables; this makes it necessary to design power connectors to communicate and seal pressure between isolated production areas and the exterior through the wellhead.
Nowadays, there are power connectors in the market, called penetrators, manufactured by American and European corporations which models are known as close socket penetrator, uncut epoxy-sealed penetrators, uncut mechanically-sealed penetrators. The first uses a closed capsule called penetrator that is placed through the wellhead with an external mechanical seal and allow electrical connections (cut in the cable) to the inner part of the head (pressurized) and to the outer part; this generates hot spots that decrease the electrical rating of the cable and creates a risk of power failure that must be minimized using delayed connection procedures (up to 5 hours) and that require controlled environmental conditions (relative temperature and humidity) that in most of the operations are variables that cannot be controlled easily; moreover, if a power failure occurred in these connections under the head, they would require the intervention of a special oil well repair and service crew called Work Over, which calling is expensive and undesirable. The uncut epoxy-sealed penetrators allow the users to avoid cutting the conductors because they use the principle of not making electrical connections to the pressurized area; they use a sealing system under the wellhead that comprises a capsule with a seal or gasket and epoxy fillers (that need controlled environmental conditions under the risks above mentioned) and that passes the cable through the head without cuts; however, the assembly procedure is problematic because it requires controlled environmental conditions and an epoxy mixture that can produce flaws in the sealing if it is not done properly. Also, this epoxy resin can lose sealing properties through time and expose the well to eventual leaks.
The uncut mechanically-sealed penetrator does not use epoxy resins; thus, it produces a mechanical sealing based on conical gaskets placed upon conical bores that once they are compressed through the use of a thread, they strangle or press the three conductors (the only sealing alternative) and create a one-way seal; however, it does not consider the measurements of the various types of cable in the market and this condition creates a risk of leaks because the cables cannot be sufficiently tightened; or, otherwise, it can damage the conductor if it is tightened more than necessary; likewise, the different sizes of conductors require different gaskets; therefore, there is a risk of installing a gasket of the wrong size; also, this system is based on the retention of pressure only in the gasket; through time, this continued condition can make the gasket fail and lead to an inevitable pressure leak that can cause incidents, such as those well known cases in productive wells in Colombia. Finally, all these systems were designed only to create a one-way seal under the head and in groups of three conductors, which limits the number of applications that the users can give in accordance with the well completion and reaction in case of a failure without having to use Work Over crews.